The dynamical framework of the nine-level version of the IAP AGCM is presented in this paper. The emphasis of the model's description is put on the following two aspects:(1) A model's standard atmosphere, whic...The dynamical framework of the nine-level version of the IAP AGCM is presented in this paper. The emphasis of the model's description is put on the following two aspects:(1) A model's standard atmosphere, which is a satisfactory approximation to the observed troposphere and lower stratosphere standard atmosphere, is introduced into the equations of the model to permit a more accurate calculation of the vertical transport terms, especially near the tropopause; (2) The vertical levels of the model are carefully selected to guarantee a smooth dependence of layer thickness upon pressure in order to reduce the truncation error involved in the unequal interval vertical finite-differencing. For testing the model, two kinds of linear baroclinic Rossby-Haurwitz waves, one of which has a dynamically stable vertical structure and the other has a relatively unstable one, are constructed to provide initial conditions for numerical experiments. The two waves have been integrated for more than 300 days and 100 days respectively by using the model and both of them are propagating westward with almost identical phase-speed during the time period of the integrations. No obvious change of the wave patterns is found at the levels in the model's troposphere. The amplitudes of both two waves at the uppermost level, however, exhibit rather significant oscillation with time, of which the periods are exactly 20 days and 25 days espectively.The explanation of this interesting phenomena is still under investigation.展开更多
多电平逆变技术是大容量变频调速的首选方案,结合多相电机技术可以进一步提升调速系统的容量。本文对中点钳位(neutral point clamped,NPC)型三电平逆变器供电的10 k W、九相磁通切换永磁(flux-switching permanent magnet,FSPM)电机调...多电平逆变技术是大容量变频调速的首选方案,结合多相电机技术可以进一步提升调速系统的容量。本文对中点钳位(neutral point clamped,NPC)型三电平逆变器供电的10 k W、九相磁通切换永磁(flux-switching permanent magnet,FSPM)电机调速系统进行了仿真和实验研究,探索结合多电平逆变技术和多相电机技术的调速方案。在三相FSPM电机矢量控制的基础上扩展建立了九相FSPM电机的定子磁场定向矢量控制方法,分析了调速系统采用两种载波PWM方式下产生的电压和电流波形。另外,3、5、7次谐波电流的解耦闭环控制成功消除了直流侧中点电位偏移。最后仿真和实验结果证明了理论分析的正确性和有效性。展开更多
文摘The dynamical framework of the nine-level version of the IAP AGCM is presented in this paper. The emphasis of the model's description is put on the following two aspects:(1) A model's standard atmosphere, which is a satisfactory approximation to the observed troposphere and lower stratosphere standard atmosphere, is introduced into the equations of the model to permit a more accurate calculation of the vertical transport terms, especially near the tropopause; (2) The vertical levels of the model are carefully selected to guarantee a smooth dependence of layer thickness upon pressure in order to reduce the truncation error involved in the unequal interval vertical finite-differencing. For testing the model, two kinds of linear baroclinic Rossby-Haurwitz waves, one of which has a dynamically stable vertical structure and the other has a relatively unstable one, are constructed to provide initial conditions for numerical experiments. The two waves have been integrated for more than 300 days and 100 days respectively by using the model and both of them are propagating westward with almost identical phase-speed during the time period of the integrations. No obvious change of the wave patterns is found at the levels in the model's troposphere. The amplitudes of both two waves at the uppermost level, however, exhibit rather significant oscillation with time, of which the periods are exactly 20 days and 25 days espectively.The explanation of this interesting phenomena is still under investigation.
文摘多电平逆变技术是大容量变频调速的首选方案,结合多相电机技术可以进一步提升调速系统的容量。本文对中点钳位(neutral point clamped,NPC)型三电平逆变器供电的10 k W、九相磁通切换永磁(flux-switching permanent magnet,FSPM)电机调速系统进行了仿真和实验研究,探索结合多电平逆变技术和多相电机技术的调速方案。在三相FSPM电机矢量控制的基础上扩展建立了九相FSPM电机的定子磁场定向矢量控制方法,分析了调速系统采用两种载波PWM方式下产生的电压和电流波形。另外,3、5、7次谐波电流的解耦闭环控制成功消除了直流侧中点电位偏移。最后仿真和实验结果证明了理论分析的正确性和有效性。
